from Vector import *

class Ray:
  
  o,d = Vector(),Vector()
  
  def __init__(self, _o=[0,0,0], _d=[0,0,-1]):
    self.o = Vector(_o)
    self.d = Vector(_d)
    
  def __str__(self): return "Ray %s %s" % (str(self.o), str(self.d))
  
  def P(self,t): return self.o + t * self.d
